协同装配信息集成建模及装配顺序规划研究

研究了装配的参照元素、装配方式、装配关系，并总结出三大装配类型．针对协同装配活动的需求，提出包含设计技术决策和产品社会属性信息在内的广义装配建模思想；在引人装配结和装配链概念的基础上，构建了适合协同装配的装配信息模型．通过搜索模型，容易获得产品装配关系图，再经过界定装配导元属性，依据自定义修剪规则，形成具有装配层次和顺序属性的同心圆图，从而能够有效地获得可行的产品装配顺序．     

基于协同虚拟环境的装配设计系统

针对分布式环境中复杂产品协同开发的装配设计需求,研究基于协同虚拟环境的装配设计系统的体系结构和关键技术,提出分布式条件下支持多用户实时交互操作的协同虚拟装配方法,包括复杂场景高分辨率实时渲染和多通道沉浸输出方案。以此为基础开发分布式协同虚拟装配环境,并通过面向汽车整车的多用户协同虚拟装配实例验证了系统的有效性。结果证明,用户可在该系统中完成复杂产品的协同虚拟装配设计工作。     

基于RDF/XML的装配语义建模研究

为解决异构CAD系统集成及协同装配设计过程中的信息共享问题,在分析装配特征语义信息的基础上,提出了面向协同设计的三元装配语义模型,提出采用RDF／XML表达装配语义元模型,并讨论了基于XML的数据集成关键技术。在文章的最后通过具体的CAD系统实现协同设计过程实例,验证了该模型及实现方法的有效性和可行性。     

基于Web的三维协同设计模型及其关键技术

为在虚拟环境下进行产品异地实时设计和装配,提出一种基于Web的三维协同设计模型.该模型使用户既可以通过浏览器在客户端的虚拟场景中进行个性化设计,也可以与其他用户进行协同设计.通过详细分析协同设计过程,研究任意形状基本实体的表征、零件扩展属性的描述、基本操作的表示、零件之间装配关系和部件运动仿真属性等的建立.基于ACIS和ECSG的三维造型技术和层次细节模型的生成算法,研发以某产品为对象的原型系统,证实该三维协同设计模型的可行性和先进性.     

基于B/S结构的协同装配的关键技术

分析了协同设计中协同装配的应用模式。在具备协同感知的前提下针对同步协同装配和异步协同装配两种应用模式分别提出对应的体系结构设计。提出基于B／S结构协同装配的具体实现方法，并实现了一套基于B／S结构的协同装配工具。     

分布式虚拟装配训练通用平台研究

针对当前部队训练中存在大量协同装配训练的问题,对基于系统通用性的分布式虚拟装配训练通用平台进行研究,提出了平台的功能模块和体系结构,研究了层次化装配体模型构建、基于运动副自由度规约的运动仿真、分布式虚拟训练以及碰撞检测等关键技术,开发并实现了分布式虚拟装配训练通用平台;实验结果表明,该平台能够满足协同装配的训练需求,且具有很好的通用性。     

虚拟装配的协同设计研究

讨论了工程中虚拟装配协同设计的几个关键元素,给出了设计的策略,分析了协同设计的效率,为深入研究虚拟装配的协同设计方法提供了有力支撑。     

基于工作流驱动的航天产品分布式协同设计环境

在分析目前航天产品研制面临形势和存在问题的基础上,引入了构建分布式协同设计环境的解决途径,同时针对产品协同设计过程中知识、任务、对象、人员和流程的统一描述问题,提出了协同设计环境中定义和运行的唯一数据源——任务统一模型(Task Unified Model,简称为TUM)的概念,并对TUM定义、组织、视图转换及运行机制进行了详细论述。然后基于Eclipse RCP和Web Portal技术构建了分布式协同设计环境APEngine,实现了面向产品设计全过程的 TUM 建模、实例化和运行过程。最后通过某航天历史型号设计的工程实际应用,证明了本文研究成果具有较强的工程应用价值。     

PDM系统数字化装配工艺管理技术研究

数字化装配工艺设计管理系统,以产品研制为应用背景,基于企业统一的PDM平台,实现数字化、结构化装配工艺设计,可视化、流程化装配工艺数据管理。向上连接设计制造协同、工艺流水、工艺BOM系统,向下与ERP和MES系统紧密集成,形成企业信息化建设主体架构,支撑公司业务创新与发展。     

多用户协同虚拟装配网格系统研究

针对复杂产品协同虚拟装配仿真应用中存在的协同交互能力差、计算资源短缺、资源动态调度分配难、规模易受限制等问题,提出了一种借鉴网格体系结构的多用户协同虚拟装配网格平台方案,介绍了系统中仿真计算资源的类型及功能,进而提出了面向服务的仿真计算资源服务化封装方法,同时还给出了系统资源管理、任务管理与调度等部分关键技术的解决方案.最后将原型系统用于某汽车多用户异地协同装配仿真验证了该系统的有效性.     

A framework for collaborative top-down assembly design

This paper presents a new system framework for collaborative top-down assembly design. Different from current computer-aided design (CAD) systems, the framework allows a group of designers to collaboratively conduct product design in a top-down manner. In our framework, a multi-level and distributed assembly model is adopted to effectively support collaborative top-down assembly design. Meanwhile, fine-granularity collaborative design functionalities are provided. First, the coupled structural parameters involved in the distributed skeleton models of the product can be collaboratively determined by the correlative designers based on fuzzy and utility theory. Second, agent based design variation propagation is achieved to ensure the consistency of the multi-level and distributed assembly model during the whole design process. Third, collaborative design of assembly interfaces between the components assigned to different designers is supported. The prototype implementation shows that our framework works well for supporting practical collaborative top-down assembly design.     

Collaborative virtual prototyping of product assemblies over the Internet

Product assembly design is a complex activity involving collaboration between several designers. Currently, many manufacturing firms out source the design and development of different portions of a product to different suppliers. Due to the absence of an integrated tool for collaborative product assembly design, designers currently follow an indirect approach. This makes collaboration an unorganized and inefficient activity. This paper discusses the architectural novelties and design considerations utilized to develop an integrated collaborative assembly design tool. Further, the scenarios of using such a tool are discussed in detail. This discussion highlights how the tool contributes towards making collaboration an organized and efficient activity and enables designers to rapidly design and prototype the product assembly.     

Ontology-based assembly design and information sharing for collaborative product development

To realize a truly collaborative product design and development process, effective communication among design collaborators is a must. In other words, the design intent that is imposed in a product design should be seized and interpreted properly; heterogeneous modeling terms should be semantically processed both by design collaborators and intelligent systems. Ontologies in the Semantic Web can explicitly represent semantics and promote integrated and consistent access to data and services. Thus, if an ontology is used in a heterogeneous and distributed design collaboration, it will explicitly and persistently represent engineering relations that are imposed in an assembly design. Design intent can be captured by reasoning, and, in turn, as reasoned facts, it can be propagated and shared with design collaborators. This paper presents a new paradigm of ontology-based assembly design. In the framework, an assembly design (AsD) ontology serves as a formal, explicit specification of assembly design so that it makes assembly knowledge both machine-interpretable and to be shared. An Assembly Relation Model (ARM) is enhanced using ontologies that represent engineering, spatial, assembly, and joining relations of assembly in a way that promotes collaborative assembly information-sharing environments. In the developed AsD ontology, implicit AsD constraints are explicitly represented using OWL (Web Ontology Language) and SWRL (Semantic Web Rule Language). This paper shows that the ability of the AsD ontology to be reasoned can capture both assembly and joining intents by a demonstration with a realistic mechanical assembly. Finally, this paper presents a new assembly design information-sharing framework and an assembly design browser for a collaborative product development.     

Design formalism for collaborative assembly design

Joints in product design are common because of the limitations of component geometric configurations and material properties, and the requirements of inspection, accessibility, repair, and portability. Collaborative product design is emerging as a viable alternative to the traditional design process. The collaborative assembly design (AsD) methodologies are needed for distributed product development. Existing AsD methodologies have limitations in capturing the non-geometric aspects of designer's intent on joining and are not efficient for a collaborative design environment. This paper introduces an AsD formalism and associated AsD tools to capture joining relations and spatial relationship implications. This AsD formalism allows the joining relations to be modeled symbolically for computer interpretation, and the model can be used for inferring mathematical and physical implications. An AsD model generated from the AsD formalism is used to exchange AsD information transparently in a collaborative AsD environment. An assembly relation model and a generic assembly relationship diagram are to capture assembly and joining information concisely and persistently. As a demonstration, the developed AsD formalism and AsD tools are applied on a connector assembly with arc weld and rivet joints.     

A knowledge intensive multi-agent framework for cooperative/collaborative design modeling and decision support of assemblies

Multi-agent modeling has emerged as a promising discipline for dealing with decision making process in distributed information system applications. One of such applications is the modeling of distributed design or manufacturing processes which can link up various designs or manufacturing processes to form a virtual consortium on a global basis. This paper proposes a novel knowledge intensive multi-agent cooperative/collaborative framework for concurrent intelligent design and assembly planning, which integrates product design, design for assembly, assembly planning, assembly system design, and assembly simulation subjected to econo-technical evaluations. An AI protocol based method is proposed to facilitate the integration of intelligent agents for assembly design, planning, evaluation and simulation process. A unified class of knowledge intensive Petri nets is defined using the O-O knowledge-based Petri net approach and used as an AI protocol for handling both the integration and the negotiation problems among multi-agents. The detailed cooperative/collaborative mechanism and algorithms are given based on the knowledge objects cooperation formalisms. As such, the assembly-oriented design system can easily be implemented under the multi-agent-based knowledge-intensive Petri net framework with concurrent integration of multiple cooperative knowledge sources and software. Thus, product design and assembly planning can be carried out simultaneously and intelligently in an entirely computer-aided concurrent design and assembly planning system.     

基于上下文的分布式协同过滤推荐技术

针对传统协同过滤推荐技术应用于大规模动态数据集时难以兼顾准确度和效率的问题,提出一种基于上下文的分布式协同过滤推荐技术,引入推荐上下文的概念,并在此基础上充分考虑用户的即时兴趣以提高推荐的准确度,采用评分矩阵的分布式存储和计算以提高推荐的效率。实验结果表明,该分布式协同过滤技术能同时保证推荐的准确度和效率,使其在大规模动态数据集上的应用更具优势。     

Tool selection-embedded optimal assembly planning in a dynamic manufacturing environment

This paper presents an approach for tool selection-embedded optimal assembly planning in dynamic manufacturing environments. It aims to embed assembly tools into the planning process of assembly sequences in a dynamic shop-floor. The experimental results demonstrate that the developed approach is efficient and practical for a high fidelity assembly sequence with alternatives of assembly-tool sets. The dynamic assembly planning can efficiently support product assembly by generating feasible assembly sequences. It provides an effective design-aiding tool to virtually deal with various what-if scenarios regarding product assembly. In particular, the Web-based application developed in this research can be incorporated into a high-performance design and manufacturing environment on the Web, forming a distributed, collaborative and globally networked tool for product assembly planning.     

Human motion prediction for human-robot collaboration

In human-robot collaborative manufacturing, industrial robots would work alongside human workers who jointly perform the assigned tasks seamlessly. A human-robot collaborative manufacturing system is more customised and flexible than conventional manufacturing systems. In the area of assembly, a practical human-robot collaborative assembly system should be able to predict a human worker’s intention and assist human during assembly operations. In response to the requirement, this research proposes a new human-robot collaborative system design. The primary focus of the paper is to model product assembly tasks as a sequence of human motions. Existing human motion recognition techniques are applied to recognise the human motions. Hidden Markov model is used in the motion sequence to generate a motion transition probability matrix. Based on the result, human motion prediction becomes possible. The predicted human motions are evaluated and applied in task-level human-robot collaborative assembly.